DIEP Flap Weights in Immediate 1-stage and 2-stage Breast Reconstruction: Considering Chest Wall Deformity

Abstract

Background: There are advantages and disadvantages to both immediate 1-stage and 2-stage autologous-breast reconstruction. The 2-stage procedure may suffer from a hitherto overlooked difficulty: the tissue expander may induce chest wall depression that may require using a heavier-than-expected flap to generate symmetrical breasts. We conducted a retrospective observational study to assess this phenomenon.

Methods: Consecutive patients who underwent 1-stage or 2-stage unilateral autologous-breast reconstruction with a deep inferior epigastric perforator flap were included. The 2 groups were compared in terms of age, body mass index, mastectomized tissue weight, inset-flap weight, and percentage additional flap weight (defined as [inset-mastectomy]/mastectomy × 100). The latter reflects the amount of additional flap tissue relative to mastectomized tissue that was needed to generate symmetrical breasts. The chest wall deformity after tissue expansion in the 2-stage patients was quantitated with computed tomography.

Results: Patients' healthy and affected breasts were symmetrical before surgery (P > 0.05). Compared with the 1-stage patients (n = 37), the 2-stage patients (n = 31) only differed in terms of a significantly higher mean percentage additional flap weight (28% versus 12%, P = 0.0077). Relative to preoperative values, nearly all 2-stage patients had mild (74%) or moderate (19%) chest wall deformity before tissue expander removal.

Conclusions: Due to tissue expander-induced chest wall deformity, 2-stage breast reconstruction may require a larger flap volume than is anticipated on the basis of preoperative volumetric measurements. Considering this phenomenon when choosing between immediate 1-stage and 2-stage reconstruction could potentially help improve patient outcomes.

Fig. 1.

Measurement of the CDI. Representative transverse CT images of a patient undergoing 2-stage autologous-breast reconstruction are shown. The distance from the top of the fourth rib to the bottom of the rib cage was measured for both the healthy (1) and affected (2) sides (A) before mastectomy (generating L1 and L2 measurements, respectively) and (B) just before tissue expander removal (generating P1 and P2 measurements, respectively). CDI was calculated as (P2/P1)/(L2/L1).

Fig. 2.

Representative case of immediate 1-stage reconstruction with a DIEP flap. A, The patient was a 49-year-old woman with left-sided invasive ductal carcinoma of the breast. B, The flap was designed, after which nipple-sparing mastectomy, sentinel lymph node biopsy, and reconstruction were conducted in one operation. C, The mastectomy specimen. D, The DIEP flap. E, View of the patient 15 months after surgery.

Fig. 3.

Representative case of immediate 2-stage reconstruction with a DIEP flap. A, The patient was a 46-year-old woman with left-sided ductal carcinoma in situ of the breast who underwent nipple-sparing mastectomy, sentinel lymph node biopsy, and tissue expander insertion in the first operation. B, Mastectomy specimen. C, Seven months later, reconstruction with a DIEP flap was performed. D, View of the patient 17 months after reconstruction.